Actually, that’s a “won’t be available”.
iTunes displays the art from the tags embedded in the song itself. For AIFF, it doesn’t support embedded art, so iTunes won’t be able to get that remotely.
For aac and mp3, the file is actually modified on the way through mt-daapd so that it looks like the art is actually embedded in the tags of the file. That’s how that works.
So short answer is no, can’t do it.